Essential IMS training course description

The IP Multimedia Core Network Subsystem (IMS) is defined by 3GPP as a new mobile infrastructure. This course studies the discreet elements in the IMS.

What will you learn

• Describe the IMS.
• Describe the IMS architecture.
• Explain how charging, security and QoS is handled in the IMS.
• Explain how the IMS supports service enablers such as Push to talk and Presence.

Essential IMS training course details

Essential IMS training course contents

• Mobile communications review

The role of IP in telecommunications. GSM to IMS. Enhanced multimedia services, Push To, convergence, conferencing, roaming.

• What is IMS?

What it is, why IMS, standard bodies: 3GPP, IETF, OMA, IMS services. MMD comparison.

• IMS architecture blocks

Overview, IMS functions, IMS interfaces, IMS protocols, IMS elements, IMS reference points. Access network, IMS in GSM, CDMA, WiFi & PSTN networks. Core network. Application, Control and Call planes.

• HSS – User database

Identification. The user database, role of HSS, SLF and multiple HSSs. “Normal” identities, IMPI, IMPU.

• IMS signalling: SIP

What is SIP? SIP URI, contact address, UAs, Proxies, basic SIP call flow, SIP sessions.

• IMS other protocols

Megaco, Diameter, XML, XCAP, COPS, RTP/RTCP, SDP, H.324M, IM and MSRP.

• Call/Session Control

Call Session Control Functions (CSCF). Domains. Home networks, visited networks. CSCF and SIP. P-CSCF, P-CSCF discovery, P-CSCF functions. I-CSCF, DNS and I-CSCF. S-CSCF, S-CSCF functions, ENUM lookups. QoS. Example call flows.

• IMS services

Open service platform, Application Servers, profiles, AS interface with S-CSCF. “Normal” services (Caller ID, Call waiting, transfer…) Push to talk Over Cellular (PoC), IMS conferencing, Group management, IMS Presence, IMS Messaging. Other possible applications. Media servers. (MRFC, MRFP).

• Gateways

IMS PSTN procedures, BGCF, PSTN interface. SGW, MGCF, MGW

• Charging

Architecture, Offline, online and flow based charging, charging reference points, CCF, DIAMETER, ICID, IOI.

• IMS security

IMS security architecture, identities, AAA, public and private user ID, service filters, Cx interface, RADIUS, Diameter protocol, 3GPP AKA, integrity, privacy, NDS, IPSEC, trust, assertion.

Learning path

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